diff --git a/src/objective-c/GRPCClient/GRPCCall.h b/src/objective-c/GRPCClient/GRPCCall.h
index fcda4dc8acd..7f80c17f1f3 100644
--- a/src/objective-c/GRPCClient/GRPCCall.h
+++ b/src/objective-c/GRPCClient/GRPCCall.h
@@ -156,15 +156,13 @@ extern NSString *const kGRPCTrailersKey;
 @optional
 
 /**
- * Issued when initial metadata is received from the server. The task must be scheduled onto the
- * dispatch queue in property \a dispatchQueue.
+ * Issued when initial metadata is received from the server.
  */
 - (void)receivedInitialMetadata:(nullable NSDictionary *)initialMetadata;
 
 /**
  * Issued when a message is received from the server. The message is the raw data received from the
- * server, with decompression and without proto deserialization. The task must be scheduled onto the
- * dispatch queue in property \a dispatchQueue.
+ * server, with decompression and without proto deserialization.
  */
 - (void)receivedRawMessage:(nullable NSData *)message;
 
@@ -172,8 +170,7 @@ extern NSString *const kGRPCTrailersKey;
  * Issued when a call finished. If the call finished successfully, \a error is nil and \a
  * trainingMetadata consists any trailing metadata received from the server. Otherwise, \a error
  * is non-nil and contains the corresponding error information, including gRPC error codes and
- * error descriptions. The task must be scheduled onto the dispatch queue in property
- * \a dispatchQueue.
+ * error descriptions.
  */
 - (void)closedWithTrailingMetadata:(nullable NSDictionary *)trailingMetadata
                              error:(nullable NSError *)error;
diff --git a/src/objective-c/ProtoRPC/ProtoRPC.h b/src/objective-c/ProtoRPC/ProtoRPC.h
index dc776368a8f..569aaa79e4d 100644
--- a/src/objective-c/ProtoRPC/ProtoRPC.h
+++ b/src/objective-c/ProtoRPC/ProtoRPC.h
@@ -31,13 +31,11 @@ NS_ASSUME_NONNULL_BEGIN
 @optional
 
 /**
- * Issued when initial metadata is received from the server. The task must be scheduled onto the
- * dispatch queue in property \a dispatchQueue. */
+ * Issued when initial metadata is received from the server.
 - (void)receivedInitialMetadata:(nullable NSDictionary *)initialMetadata;
 
 /**
  * Issued when a message is received from the server. The message is the deserialized proto object.
- * The task must be scheduled onto the dispatch queue in property \a dispatchQueue.
  */
 - (void)receivedProtoMessage:(nullable GPBMessage *)message;
 
@@ -45,8 +43,7 @@ NS_ASSUME_NONNULL_BEGIN
  * Issued when a call finished. If the call finished successfully, \a error is nil and \a
  * trainingMetadata consists any trailing metadata received from the server. Otherwise, \a error
  * is non-nil and contains the corresponding error information, including gRPC error codes and
- * error descriptions. The task must be scheduled onto the dispatch queue in property
- * \a dispatchQueue.
+ * error descriptions.
  */
 - (void)closedWithTrailingMetadata:(nullable NSDictionary *)trailingMetadata
                              error:(nullable NSError *)error;
diff --git a/src/objective-c/tests/APIv2Tests/APIv2Tests.m b/src/objective-c/tests/APIv2Tests/APIv2Tests.m
index 28f94cd8c77..e49f58ae9d3 100644
--- a/src/objective-c/tests/APIv2Tests/APIv2Tests.m
+++ b/src/objective-c/tests/APIv2Tests/APIv2Tests.m
@@ -82,28 +82,22 @@ static const NSTimeInterval kTestTimeout = 16;
 }
 
 - (void)receivedInitialMetadata:(NSDictionary *_Nullable)initialMetadata {
-  dispatch_async(_dispatchQueue, ^{
-    if (self->_initialMetadataCallback) {
-      self->_initialMetadataCallback(initialMetadata);
-    }
-  });
+  if (self->_initialMetadataCallback) {
+    self->_initialMetadataCallback(initialMetadata);
+  }
 }
 
 - (void)receivedRawMessage:(GPBMessage *_Nullable)message {
-  dispatch_async(_dispatchQueue, ^{
-    if (self->_messageCallback) {
-      self->_messageCallback(message);
-    }
-  });
+  if (self->_messageCallback) {
+    self->_messageCallback(message);
+  }
 }
 
 - (void)closedWithTrailingMetadata:(NSDictionary *_Nullable)trailingMetadata
                              error:(NSError *_Nullable)error {
-  dispatch_async(_dispatchQueue, ^{
-    if (self->_closeCallback) {
-      self->_closeCallback(trailingMetadata, error);
-    }
-  });
+  if (self->_closeCallback) {
+    self->_closeCallback(trailingMetadata, error);
+  }
 }
 
 - (dispatch_queue_t)dispatchQueue {
diff --git a/src/objective-c/tests/InteropTests.m b/src/objective-c/tests/InteropTests.m
index dcc8f1b589a..8754bd5ccaf 100644
--- a/src/objective-c/tests/InteropTests.m
+++ b/src/objective-c/tests/InteropTests.m
@@ -103,28 +103,22 @@ BOOL isRemoteInteropTest(NSString *host) {
 }
 
 - (void)receivedInitialMetadata:(NSDictionary *)initialMetadata {
-  dispatch_async(_dispatchQueue, ^{
-    if (_initialMetadataCallback) {
-      _initialMetadataCallback(initialMetadata);
-    }
-  });
+  if (_initialMetadataCallback) {
+    _initialMetadataCallback(initialMetadata);
+  }
 }
 
 - (void)receivedProtoMessage:(GPBMessage *)message {
-  dispatch_async(_dispatchQueue, ^{
-    if (_messageCallback) {
-      _messageCallback(message);
-    }
-  });
+  if (_messageCallback) {
+    _messageCallback(message);
+  }
 }
 
 - (void)closedWithTrailingMetadata:(NSDictionary *)trailingMetadata
                              error:(NSError *)error {
-  dispatch_async(_dispatchQueue, ^{
-    if (_closeCallback) {
-      _closeCallback(trailingMetadata, error);
-    }
-  });
+  if (_closeCallback) {
+    _closeCallback(trailingMetadata, error);
+  }
 }
 
 - (dispatch_queue_t)dispatchQueue {